1. Field of the Invention
The present invention relates to a working machine having blades as soil pressing attachments.
2. Description of the Related Art
For example in Japanese Patent Laid-Open No. 2003-239318 there is described a working machine having as blades a body blade attached to the working machine and a pair of extension blades attached to both end portions in the longitudinal direction of the body blade, thereby serving as extensions of the body blade.
The working machine disclosed in the above publication is provided with a mounting pin vertically inserted removably through mounting holes formed in the main blade (body blade) and also through to-be-mounted holes formed in the extension blades, thereby connecting the main blade and the extension blades with each other, and rotation preventing means for preventing both blades from rotating around the pins. With the rotation preventing means, the extension blades are held unrotatably with respect to the main blade and in an extended attitude from the main blade.
More particularly, the rotation preventing means cause front or rear portions of the extension blades to be abutted against a rear edge of the main blade to inhibit a forward or backward movement (hereinafter referred to as “longitudinal movement”) of the extension blades with respect to the main blade, thereby preventing rotation around the mounting pin.
With this blade device, however, it is necessary that the mounting holes and the to-be-mounted holes of both blades be subjected to mutual alignment (superposition) at the time of inserting the mounting pin through both blades. In this case, before insertion of the mounting pin, the mounting holes and the to-be-mounted holes can be aligned with each other longitudinally by bringing both blades into abutment with each other longitudinally. In this state, however, for superposing the mounting holes and the to-be-mounted holes vertically, it has so far been required to move both blades in the transverse direction while searching for the mounting holes and the to-be-mounted holes.
Thus, when superposing the mounting holes and the to-be-mounted holes one on the other in this blade device, it has so far been required to perform such complicated operations as first fixing longitudinal positions of the main blade and the extension blades by the rotation preventing means to align the mounting holes and the to-be-mounted holes with each other longitudinally and subsequently sliding both blades right and left relative to each other to adjust transverse positions of the mounting holes and the to-be-mounted holes.